Fuel cell systems installed in vehicles are provided with an inverter for supplying electrical power to a motor from a fuel cell and an energy storage device. For example, Patent Publication JP-A-2005-348530 discloses a fuel cell system provided with two DC-DC converters in addition to an inverter. These consist of a first DC-DC converter that supplies electrical power to the inverter while controlling output voltage of the fuel cell, and a second DC-DC converter that supplies electrical power of an energy storage device while controlling input voltage of the inverter (Patent Literature 1).
According to the invention described in Patent Literature 1, by controlling the first DC-DC converter and setting the output voltage value of the fuel cell to within the range between a maximum value and minimum value of the circuit voltage of the energy storage device, the frequency of execution of a voltage conversion operation can be reduced, thereby making it possible to suppress increases in power loss (Paragraph 0012).
In addition, with respect to controlling power conversion of the inverter, Patent Literature 1 describes that a torque command is calculated based on a signal of an accelerator depression amount related to the amount of depressing operation of an accelerator pedal by a driver, the torque signal is input to the inverter, and current of each phase is output to each phase of the motor in order to generate the required torque (paragraph 0023).